Bonsai Myths-- Water Droplet

View previous topic View next topic Go down

Bonsai Myths-- Water Droplet

Post  Kev Bailey on Sun Jun 13, 2010 10:13 pm

I was going to seek your assistance in forever putting to bed the myth that water droplets on leaves can burn them. I decided to do a quick Google and look what I came up with - http://arago.elte.hu/files/WaterDropOnLeaf_NewPhytologist-Commentary-Jones.pdf

If anyone has anything to add, I'd appreciate it.


Last edited by Chris Cochrane on Wed Jun 16, 2010 12:31 am; edited 1 time in total (Reason for editing : title clarification)

_________________
“It is not the strongest of the species that survives, nor the most intelligent. It is the one that is the most adaptable to change.” - Charles Darwin.

Kev Bailey
Admin


Back to top Go down

Bonsai Myths

Post  Guest on Sun Jun 13, 2010 10:41 pm

I thought the focal point of a water droplet had been proved to be way past the back of the leaf?

Guest
Guest


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  Mike Jones on Mon Jun 14, 2010 6:25 am

Kev

On another forum this subject came up recently and I was shot down in flames for suggesting that it does burn (not all species of course) and IMHO, overhead watering in the midday sun is just plain daft. I learnt by my mistakes of 25 years ago. I water in the evening since then, when the sun is down, everything is at peace, the birds are getting ready for their zzzz's, beer in hand and so on.

YES it does burn certain leaf types. I will not be swayed.

Mike

Mike Jones
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  JimLewis on Mon Jun 14, 2010 12:31 pm

Sway or not, it is basic physics; there has to be some distance between the drop (lens) and the leaf (focal plane) and it would have to be a precise distance relative to the size and diameter of the drop in order to have the light focused into a pin-sized spot. Since the water is sitting on the leaf, there's no focal length. You can prove this by laying a magnifying glass on your hand in bright sunlight. Nothing happens. Lift the lens and focus the sunlight and . . . OUCH!

If your water has something in it that is left behind when the water evaporates (acid from acid rain???), it is conceivable that whatever that material is could do damage to the leaf. But that's it.

Andy Walsh, another old IBCer I've heard little of recently, gave us a detailed explanation of the physics behind this most hoary of horticultural myths way back in the early mailing-list days of the IBC. Alas, it was lost during one of my many computer change-overs. But this article does the job, too.

I had started an article on bonsai myths -- there are a LOT of them -- but a quick search here failed to find it. I'll keep looking.

_________________
Jim Lewis - lewisjk@windstream.net - Western NC - People, when Columbus discovered this country, it was plumb full of nuts and berries. And I'm right here to tell you the berries are just about all gone. Uncle Dave Macon, old-time country musician

JimLewis
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  AlainK on Mon Jun 14, 2010 12:46 pm

If it was the case, all the trees and plants in my neighbourhood would be badly damaged: we've had several days of hot, weather with showers of rain, and even some hail storms (fortunately not big ones in my area) sometimes lasting just a few miniutes, and very sunny and hot spells in-between.

So far, they look perfectly healthy, including my tomato plants that haven't even developed signs of the dreaded fungal diseases that are so frequent on these plants.

Not to mention the "thermic shock": water from the hose is warmer than the rain from a storm.

But of course, it is more sensible to water your trees in the evening, if only because it evaporates less quickly. So it's cheaper, and more environment-friendly.

AlainK
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  Kev Bailey on Mon Jun 14, 2010 1:55 pm

Thanks all. Jim's put into words exactly what I wanted to say and Alain's logic is unassailable.

About the only other detrimental effect I can understand is the trapping of airborne fungal spores in water and them drying onto the leaf surface, beginning a fungal attack. Is that what you were alluding to with the blight reference Alain?

_________________
“It is not the strongest of the species that survives, nor the most intelligent. It is the one that is the most adaptable to change.” - Charles Darwin.

Kev Bailey
Admin


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  EdMerc on Mon Jun 14, 2010 2:09 pm

AlainK wrote:If it was the case, all the trees and plants in my neighbourhood would be badly damaged: we've had several days of hot, weather with showers of rain, and even some hail storms (fortunately not big ones in my area) sometimes lasting just a few miniutes, and very sunny and hot spells in-between.

Exactly! If this myth where true then most of Florida would be a ravaged wasteland as it rains almost every afternoon preceded and followed by 90+ full sun days. I think anyone who has ever visited my neighborhood can attest, greenery is not an issue here.

Ed

EdMerc
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  AlainK on Mon Jun 14, 2010 3:19 pm

Kev Bailey wrote:
About the only other detrimental effect I can understand is the trapping of airborne fungal spores in water and them drying onto the leaf surface, beginning a fungal attack. Is that what you were alluding to with the blight reference Alain?

Er... Probably Embarassed

I don't know really how it works, but two years ago, most tomato plants in gardens yielded very little crop due to diseases. The leaves are very sensitive to that, and that's the only reason it is strongly recommended to water the foot, not the leaves, whether it's in the evening, in the morning, or during the day. That's why everyone uses Bordeaux mixture, which is on the most efficient preventiive treatment. But that's a different story...

AlainK
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  JimLewis on Mon Jun 14, 2010 3:42 pm

most of Florida would be a ravaged wasteland

Well, I spent 35 years in Florida's government working on environmental problems and that's not too far off base -- especially in the central and south parts.

_________________
Jim Lewis - lewisjk@windstream.net - Western NC - People, when Columbus discovered this country, it was plumb full of nuts and berries. And I'm right here to tell you the berries are just about all gone. Uncle Dave Macon, old-time country musician

JimLewis
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  EdMerc on Mon Jun 14, 2010 7:09 pm

Low blow Jim... Low blow. Sad

EdMerc
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  JimLewis on Tue Jun 15, 2010 5:21 pm

Mostly against me and all the people I worked with from Claude Kirk through Lawton Chiles. We worked hard, but it was largely fruitless, considering who really runs the state -- especially in the last 10 years or so when it has been pretty much "anything goes."

_________________
Jim Lewis - lewisjk@windstream.net - Western NC - People, when Columbus discovered this country, it was plumb full of nuts and berries. And I'm right here to tell you the berries are just about all gone. Uncle Dave Macon, old-time country musician

JimLewis
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  rock on Tue Jun 15, 2010 7:31 pm

JimLewis wrote:

I had started an article on bonsai myths -- there are a LOT of them -- but a quick search here failed to find it. I'll keep looking.

One of the best articles ever...

"Ten Great Bonsai Myths", Bonsai: Journal of the American Bonsai Society. Vol. 24, No. 1. Spring 1990 , p. 8-11. By Jerry Meislik

Check your library I bet its there... Wink

http://www.bonsaihunk.us/Fallacies.html


Last edited by Rock on Tue Jun 15, 2010 7:33 pm; edited 1 time in total (Reason for editing : turrible spelling)

rock
Member


Back to top Go down

Re: Bonsai Myths-- Water Droplet

Post  Sponsored content Today at 7:19 pm


Sponsored content


Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum